Curriculum · ENT, Ophthalmology, and Dermatology
Otosclerosis
What it is
Otosclerosis is abnormal bone remodeling in the middle ear, in which the bony labyrinth is replaced by immature spongy bone and the stapes footplate is fused to the oval window so that it cannot vibrate. The result is conductive hearing loss, which may progress to SNHL if the cochlea is involved. Three types are named: stapedial otosclerosis, which gives conductive hearing loss; cochlear otosclerosis, which gives SNHL; and histologic otosclerosis, which is asymptomatic.
Causes and risk
It is autosomal dominant, and it is a cause of deafness in young adults, between 20 and 40 years. It progresses during pregnancy. A family history of hearing loss at a young age is characteristic.
How it presents
Hearing loss is conductive and slowly progressive, often bilateral, in a young adult, with tinnitus worsening over the same period; the tinnitus may be pulsatile and vertigo may go with it. Otoscopy is unremarkable, the tympanic membrane appearing normal, at times with a pink blush or reddish hue seen through the eardrum, which is the Schwartze sign and reflects the increased vascularity, that is the neovascularization, of the otosclerotic bone.